A prominent Italian gay rights campaigner and former MP has been arrested in Sochi while watching the Winter Olympics with a banner reading “Gay Is Ok” in Russian, two activists have said.

Vladimir Luxuria, a television personality and actor who became Europe’s first openly transgender parliamentarian when she was elected to the Italian chamber of deputies, reportedly called the heads of two gay rights organisations in Rome to say she had been detained on Sunday by Russian police.

“She was arrested by the police at Sochi while she was watching the Olympics with a banner which read, in Russian, ‘Gay is ok’,” Imma Battaglia, honorary president of the Di’Gay Project, told Corriere.it.

Luxuria had also sent a text message saying: “Help me I am detained. I am alone,” she added, saying the television star had not been able to understand what police station she had been taken to.

Flavio Romani, president of ArciGay, said he had also received a telephone call from Luxuria.

The staff of Emma Bonino, the Italian foreign minister, wrote on Twitter that an crisis unit was “already active” following the arrest.

Luxuria, who was an MP for the Communist Refoundation party from 2006 until 2008, is a well-known champion of gay, lesbian, bisexual and transgender rights in Italy.

She had written on Twitter earlier on Sunday that she had arrived in Sochi, posting a photograph of herself standing in front of the Olympic rings with a rainbow-coloured fan and parasol.

Reports of her arrest provoked outrage and condemnation from senior political figures.

“Rebellious, free, unafraid of the state’s morality police. Thank you, @vladiluxuria,” wrote Nichi Vendola, the openly gay head of the Left Ecology Freedom (SEL) party, on Twitter.

Another SEL MP, Alessandro Zan, called on Italian president Giorgio Napolitano to intervene and added: “If Luxuria is not released in the next few hours, I am ready to leave for Russia and I extend the invitation to any MPs who want to join.”

A spokesman for the Italian foreign minister said he could not comment on reports of the arrest, but that the Italian consulate in Moscow had staff in Sochi who were in the process of looking into what had happened.